/Engine/Plugins/Editor/UVEditor/Source/UVEditorTools/Public/Selection/UVToolSelectionHighlightMechanic.h
Convert the unwrap selections to elements in the applied mesh, then highlight those there.
void RebuildAppliedHighlightFromUnwrapSelection ( const [TArray](API\Runtime\Core\Containers\TArray)< [FUVToolSelection](API\Plugins\UVEditorTools\Selection\FUVToolSelection) > & UnwrapSelections, bool bUsePreviews )